The present invention relates, generally, to power output, switching circuitry incorporating multiple paralleled semiconductors carrying high current or operating at high frequencies,and more particularly to power output drivers with ratings in the range of one kilowatt and above and employing signal frequencies in the range of 10 Khz, including power converters for AC to AC, DC to DC, AC to DC, DC to AC, and power amplifiers of the A, AB, B, C and D types and their various subtypes.
The performance of semiconductor circuit designs employing multiple paralleled devices operating at high currents and/or at high frequencies, e.g., above 10 Khz, is often limited by the mutual interaction of the paralleled devices. In particular, conventional power converter performance is limited in the frequency-power products available. There are high power converters in the sub-hundred kilowatt to multi-megawatt range that employ switching frequencies in the 1-kHz range using SCRs (Silicon Controlled Rectifiers), thyristors and GTOs. In the tens of kilowatt range with switching frequencies from about 1 kHz to about 10 kHz,converters often use, for example, IGBTs (Insulated Gate Bi-Polar Transistors) and Bi-Polar power devices. Higher frequency operation with IGBTs and Bi-Polar devices is accomplished with higher losses, more complexity, restrictive performance and increased expense. A particularly suitable device for high frequency converter operation is the power MOSFET (Metal Oxide Silicon Field Effect Transistors). MOSFETs are capable of switching frequencies in the MHz range and are simple to control. However, MOSFETs are subject to higher resistive losses for comparable maximum current for each device. Such losses, however, can be controlled with efficient thermal management that provides low operating junction temperatures.
Conventional converter construction and operation does not lend itself to high switching frequencies, e.g.,  greater than 10 kHz operation, without high losses. Additionally, conventional converter construction does not lend itself well to the parallel operation of power MOSFETs at high switching frequencies, due to the mutual interaction or cross-talk, between the parallel devices. The need exists for circuit designs and constructs that provide for the efficient paralleled operation of multiple devices at high currents and high signal frequencies.
The present invention provides for the substantial elimination of the generally performance degrading mutual interaction of paralleled devices in power output driver circuits employing high signal frequencies and/or high currents.
The present invention provides for the construction and operation or high frequency, high power converters.
The present invention provides for the construction and operation of high efficiency converters.
The present invention provides for the low cost construction of the output drivers for compact, high efficiency, and high frequency converters.